An actuator arranged in an optical scanning device and comprising an optical head having a focal lens is intended for emission of a light beam, in particular of a laser beam, onto an optical disk designed as an information carrier and for reception of the beam reflected by said optical disk. Therein, the optical disk is held by a supporting device and is caused to make a rotational motion. The actuator can be designed as a two-arm suspension arm actuator with the optical head being arranged at a free end thereof. The suspension arm can be pivoted about an axis and moves the end with the optical head in the form of an arc in a plane extending in parallel to the recording surface of the optical disk, tracking plane, and can be focused with its head perpendicularly to this plane, focusing plane. A suspension arm actuator allows achieving fast access to various locations on the recording carrier.
For example, such a suspension arm actuator is described in US 2004/0148619 A1. The suspension arm actuator described there is arranged on a support such that it can be pivoted about an axis and, to achieve this, comprises a magnetic drive at its end region that is arranged opposite to the optical head, said magnetic drive being formed of a magnetic arrangement permanently arranged on the support and of a coil arranged on the suspension arm, with the operating current of said coil being controlled. On the pivot axis side facing away from the magnetic drive, that is on the side of the focal lens, the suspension arm comprises an elastic region with a leaf spring arrangement, which supports the optical head at its free end. A second magnetic drive formed with the suspension arm is allocated to said elastic region on the head side thereof, said elastic region being partially enclosed by the remaining suspension arm and said second magnetic drive being able to move said free end and, thus, the head in focusing direction. This is to disadvantage in that the head-sided part of the suspension arm is intense in weight, with the result that a swivel motion of the suspension arm about the axis is accompanied by an increased inertia thereof.